What is growing/living on my shell?

[Anni]

Hi there, I just noticed this growing on 2 of my empty hermit shells. It looks like dandelion fluff. Is it just an algae or something else? It’s hard to tell from the photo but it is all over the dark shell.

 

[dwolson]

Looks like a hydroid to me but I could be wrong.

 

[Anni]

Here’s a better picture.

 

[tankstudy]

They appear to be a type of hydroid.

 

[Anni]

They appear to be a type of hydroid.

Is this something I should be concerned about? I don’t even know what hydroids are I will have to do some googling.

 

[dwolson]

Hydroids come an go. From what I've heard they are nothing to be too concerned about.

 

[tankstudy]

Is this something I should be concerned about? I don’t even know what hydroids are I will have to do some googling.

Hydroids aren't too awful but they can bother some corals. Zoas and palys are not very fond of them from my experience. You think your water parameters are off or something but upon closer inspection you'll see hydroids agitating them.

Sometimes they go away and other times you'll have to accept their existence. I have hydroids myself and I just kind of accept their existence. If they bother my corals too much, I just brush them off.

 

[Anni]

Hydroids aren't too awful but they can bother some corals. Zoas and palys are not very fond of them from my experience. You think your water parameters are off or something but upon closer inspection you'll see hydroids agitating them.

Sometimes they go away and other times you'll have to accept their existence. I have hydroids myself and I just kind of accept their existence. If they bother my corals too much, I just brush them off.

Ok thanks for the info! I’ll just remove the shells they are growing on. I’ve found a few larger brown ones growing on a zoa frag so I’ll scrape those off too.